[R] Coloring spaces between lines in xyplot

[Jim Lemon]

Seth W Bigelow wrote:
> Ok, thanks to Carl Witthoft I now know that to color spaces between  and
> below a pair of lines in xyplot, I will need to redefine the lines as
> polygons, and use the lpolygon panel function, as in the following
>
> library(lattice)
> p <- c(1,10,10,1)       #  vector of x values
> q <- c(4,29.2,16,2.5)          # vector of y values for upper polygon
> r <- c(2.5,16,0,0)                    # vector of y values for lower
> polygon
>
> xyplot(
>   q + r ~ p,
>   panel = lpolygon,
>   col = c("red","green")
>   )
>
> But, having spent several hours arriving at this increment of knowlege, I
> find myself stumped at how to assign different colors to the two polygons!
> the above "col" line did not do the job.
>
>   
Hi Seth,
Maybe you could use the stackpoly function in the plotrix package:

x<-matrix(x,nrow=10)
y<-matrix(y,nrow=10)
stackpoly(x,y,stack=TRUE)

Jim